The present invention relates to a method for manufacturing a honeycomb structure. More specifically, the present invention relates to a method for manufacturing a honeycomb structure, the method being capable of improving production efficiency and raw material yield.
In various fields such as chemistry, electric power, and iron and steel, there has been employed a ceramic honeycomb structure excellent in thermal resistance and corrosion resistance as a carrier of a filter for catalyst apparatus used for environmental measures, collection of a specific substance, or the like. In particular, recently, the honeycomb structure has extensively been used as a diesel particulate filter (DPF) for trapping particulate matter (PM) discharged from a diesel engine and the like by alternately plugging opening portions of cells on both the end faces to obtain a plugged honeycomb structure. In addition, as materials for a honeycomb structure used at high temperature in a corrosive gas atmosphere, silicon carbide (SiC), cordierite, aluminum titanate (AT), and the like have suitably been employed because of excellent thermal resistance and chemical stability.
Since silicon carbide has relatively high thermal expansion coefficient, a large honeycomb structure formed by using silicon carbide as a framework may have a defect by a thermal shock upon being used. In addition, it may have a defect by a thermal shock when trapped particulate matter is combusted and removed. Therefore, regarding a honeycomb structure formed by using silicon carbide as a framework, in the case of manufacturing a honeycomb structure having a predetermined or larger size, small segments for a plugged honeycomb structure are generally manufactured, the segments are bonded together to obtain one large bonded article, and the outer periphery of the bonded article is subjected to rough processing and grinding to obtain a plugged honeycomb structure having a desired shape such as a cylindrical shape (see JP-A-2003-291054). Incidentally, a bonding material is used for bonding of the segments. The bonding material is applied on a side face of predetermined segments to bond a plurality of segments at their side faces.
When a honeycomb structure having a desired shape is manufactured by such a method, after manufacturing one large rectangular parallelepiped bonded article by bonding a plurality of rectangular parallelepiped segments, it is generally necessary to subject the outer periphery to rough processing to obtain an almost desired shape and further subject it to grinding to obtain a honeycomb structure having a desired shape with high precision. Therefore, extra steps such as a rough processing step of the outer periphery, a grinding step, and the like are necessary. In addition, since the outer periphery is subjected to rough processing and grinding, there arises a problem of low raw material yield.